A power conversion device installed on board an electric car or the like is equipped with an inverter circuit that includes a filter capacitor for stabilizing an input voltage, and a control calculator that controls the supply of electric power to the inverter circuit. For example, if damage causing a short-circuit or the like exists in the inverter circuit, the filter capacitor may not be charged even if power is supplied to the inverter circuit. If electric power continues to be supplied to the inverter circuit in this state, there is a possibility that the damage in the inverter circuit will spread. For this reason, the control calculator, after detecting incomplete charging of the filter capacitor, restricts the supply of electric power to the inverter circuit.
Generally, if some kind of malfunction occurs in the control calculator, the control calculator is restarted by an instruction from a control calculation monitor that monitors the operation of the control calculator. Even if the control calculator have been restricting the supply of electric power to the inverter circuit before being restarted, the restarted control calculator will supply electric power to the inverter circuit unless the state before the restart is saved. Since the inverter circuit is still in a damaged state, there is a possibility that the damage in the inverter circuit will spread.
Patent Literature 1 proposes technology that holds information for setting an off state in a memory. If this technology is applied to a power conversion device, information indicating that the control calculator has detected incomplete charging of the filter capacitor is held in the memory. If the restarted control calculator is operating normally, by referencing the memory, the control calculator is able to restrict the supply of electric power to the inverter circuit immediately even after restarting.